These vessels usually hold 20 to 30 people, and descend to depth of a few feet to perhaps 80 feet or more to give the passengers a close up look at the underwater world. I’ve never ridden on one, but recently was able to enjoy a close meeting with one off the coast of Maui.
It was a bright sunny day, early in the afternoon, with terrific visibility. My wife Debbie and I were diving the Carthaginian wreck. just outside Lahaina, Maui. The Cathaginian was a steel hulled turn-of- the century sailing ship that was moored in Lahaina harbor as a whaling museum for over 20 years when she was damaged by a storm. About 4 years ago she was intentionally sunk hull down in about 100 feet of water as an artificial reef and divers play ground. What remains of the ship is the intact hull which you can enter through a huge cargo opening on the deck. Inside is a single large room, no passages. It is a safe, albeit, deep recreational dive. Debbie and I swimming inside the hull with and observing a solo white tip reef shark who was with us inside the wreck, when we first heard the submarine. We exited the wreck (with the white tip along side) and saw the sub at about 75 feet, and perhaps 30 meters to the West. It carried about 24 people. They sat on a central bench, facing out each side of the submarine as each passenger looked out through their own porthole. For those facing us, we , along with our shark friend, gave them a pretty good scene to observe!
If you have ever been in the water when one of these subs goes by, you know how totally cool it is. We enjoyed waving to the passengers and received their responsive waves. We felt like a part of the attraction, along with 4 reef shark, who by then had settled onto the sandy bottom just north of the wreck. As the sub passed us by, Debbie ascended a little as I looked along the top of the wreck for frog fish and other things. Her attention was diverted as she watch the white tip and a large parrot fish get in a bit of a territory tiff, so she did not immediately notice the submarine doing an about-face to make another pass so those on the opposite side of the sub could view the wreck and things on and near it, including us.
Debbie then heard the whirr of the electric motor, turned and found that she was VERY CLOSE to the sub. By very close I mean less than ten feet. Debbie swears that it was at least twelve. It was still very close. I was a bit father off, another eight or ten feet away and below Debbie. Debbie remained calm and waved, I am sure making eye contact with each passenger, as she slowly backed off. Those on the sub with a camera got a nice close up of her, for sure. Since the submarine was about the size of the average humpback whale, being that close was really not a good idea. Debbie and I were both fortunate to have escaped any injury or entanglement. A diver could be seriously injured in a collision with one of those subs, so we learned a lesson. Enjoy the encounter, pay attention when there is a submarine in the area, and keep an appropriate distance, which I gauge to be ten meters.
We have come close to other sub encounters both in Cozumel and Grand Cayman, but always in those cases it was seeing the retreating vessel from afar. I hope we meet up with another sub one day. It was great fun, and will be again, from a discreet ten meters away. Keeping a discrete distance is just one of three rules of etiquette we formulated applicable to encounters with tourist submarines. You can read about the other two, and lots more, The Scuba Snobs Guide to Diving Etiquette BOOK 2.